1. Field of the Invention
The present invention relates to a method and apparatus for providing a communication service to a Mobile Station (MS) by a plurality of Base Stations (BSs) in cooperation in a wireless communication system.
2. Description of the Related Art
A MS included in a wireless communication system may have a virtual cell that is formed flexibly or adaptively depending on the MSs moving path. The virtual cell may be considered to be a kind of cooperative cell that is formed for cooperative communication between BSs. The cooperative cell may include at least one BS, and if the cooperative cell includes two or more BSs, the BSs may transmit the same or different data to an MS at the same time or at different times.
For example, in a case where the cooperative cell includes two BSs, one BS may allocate resources of the cooperative cell, serving as a master BS, and the other BS may provide a service to an MS in cooperation with the master BS, serving as a slave BS. Since the cooperative cell is flexibly formed depending on the moving path of the MS, the roles of the BSs are also flexible in the cooperative cell. Specifically, a master BS in a first cooperative cell may be changed to another BS, and the master BS in the first cooperative cell formed to provide a service to a first MS may operate as a slave BS in a second cooperative cell formed to provide a service to a second MS.
In the case where one BS simultaneously belongs to several different cooperative cells in this way, there is a need for a resource allocation scheme for efficiently allocating resources of each BS. The resource allocation scheme may be classified as a centralized control scheme in which a master BS of each cooperative cell allocates resources of all BSs in the cooperative cell, and a distributed control scheme in which each BS of each cooperative cell allocates its resources individually.
However, in the centralized control scheme, in a case where a BS simultaneously belongs to multiple cooperative cells, if a resource allocation command received from a master BS of each cooperative cell instructs allocation of the same resources in a duplicate manner, resource allocation conflicts may occur. In this case, if a master BS of each cooperative cell coordinates the resource allocations through signaling with other BSs in order to prevent the resource allocation conflicts, significant overhead and time delay may occur.
In addition, the distributed control scheme may not be efficient in improving the system yield through the original inter-cell cooperation of the cooperative cells. Therefore, there is a need for a resource allocation scheme capable of more efficiently allocating resources of cooperative cells.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.